This invention relates to a safety device particularly useful with an electric controlled hydraulic actuated lift and descent heavy duty loading platform, and more particularly, relates to an improved safety foot-toe guard for the protection of human limbs which guard folds upon contact to collapse away from the encountered obstacle, causing electric deactivation of platform movement.
The enactment of federal safety regulations such as the Occupational Safety and Health Act (OSHA) has brought the need to apply protective devices and safety oriented apparatus to many industrial practices, activities and equipment. One such example has been in the use of floor-recessed heavy duty hydraulic loading platforms, sometimes hereinafter commonly referred to as platform lifts, wherein during the descent of the platform, a human foot or toe could be unwittingly projected beneath the vertical side wall or outer edge of the platform into the direct path of travel thereof so as to be in jeopardy of being smashed or severed upon contact with the descending platform.
It is the field of application of the present invention to provide a collapsible folding foot-toe guard which protrudes from the extreme outer edge or side wall of the loading platform which safety guard will at once both yield to contact with a human limb as well as cause electric deactivation of the hydraulic power source which activates movement of the platform lift. One related prior art device comprises a safety toe guard within the same field of application as the present invention and is disclosed in U.S. Pat. No. 3,920,101, issued Nov. 18, 1975, for which the inventor thereof is the same inventor as for the herein disclosed invention, and the assignor thereof is not a common or related assignor to the assignor of the present invention. The present invention constitutes an improvement over the above-referenced patented safety guard. The safety toe guard of the above-referenced patent is comprised of a flexible band affixed to the side of the platform lift so as to be suspended for likely contact with the lower limb of a person standing too close to the platform lift so that the lower limb of such person would likely be trapped under the platform upon its descent. The distal edge of the flexible band is intended to brush against the leg and warn the person to move his leg. The flexible band yields upon contact but would not cause arrest of the platform movement.
The aforementioned prior art device suffers from the disadvantage of being totally independent from the power actuation means for the platform, independent from either the electric control or the actuation means or the actuators themselves. The person endangered may not sense a weak brushing contact with the flexible band and the continued movement of the platform could defeat the application of such flexible band. The flexible band of the aforementioned patent was at best cumbersome and unwidely to be accommodated within the available floor recess which encompassed and housed the fully descended platform. A visual study of the aforementioned prior art safety guard would disclose a flexible band mounted on the upper outer edge portions of a platform so as to provide a protruding flexible band having its distal edge overlapping the adjacent edge portions of the floor that define the platform receiving recess. The flexible band is thereby exposed to misuse and exaggerated wear.
The advent of OSHA regulations brought promulgated commercial standards such as Commercial Standard CS 202-56 Section 1910.30 (3) which therein specifies an inwardly sloping side wall for such platform lifts providing a planar offset between the vertical plane intersecting the top outer edge of the platform side wall and the vertical plane intersecting the lower outer edge of said side wall. The inwardly sloping side wall thus presents a camming surface itself comprising a safety feature in that any projecting foot would be engaged gradually and cammed backwards to encourage the removal of the foot. Thus, the stark vertical side walls of such platform lifts were removed by safety regulations. The sloping side wall now presents a more advantageous mounting location for an improved safety toe guard wherein the safety toe guard could be advantageously stored beneath the floor surface in a non-interfering protected location during non-use of the platform lift, wherein the safety toe guard could be brought into direct contact with the inner extremes of the protruding limb and would not be dependent upon user recognition and reaction in order to be effective, and further wherein the movement of the toe guard would be useful to effect an immediate arrest of the descending movement of the platform lift.